Quick make and quick break circuit breaker with automatic reset



Aprifi 1.958 P. Ni.- CHRISTENSEN 2,829,21

QUICK MAKE AND QUICK BREAK CIRCUIT BREAKER WITHAUTOMATIC RESET FiledFeb. 1, 1954 8 78 f; I i L A I 1.5 1% x 114 120 ATTORNEYS United StatesPatent O QUICK MAKE AND QUICK BREAK ClRCUIT BREAKER WITH AUTOMATIC RESETPaul M. Christensen, West Orange, N. J., assignor to Federal ElectricProducts Company, Newark, N. 3., a corporation of Delaware ApplicationFebruary 1, 1954, Serial No. 407,381

16 Claims. (Cl. 200-416) The present invention relates generally toautomatic ciruit breakers.

The primary object of the present invention is the provision of acircuit breaker which has a high contact closing speed and a highcontact opening speed, both of which speeds are independent of theoperator so as to provide both a quick-make and a quick-break circuitbreaker.

Another object is the provision of a quick-make, quickbreak circuitbreaker which is automatically reset upon the tripping thereof.

Another object is the provision in a circuit breaker having a movablecontact and a cooperating normally stationary contact, of a highly novelmounting arrangement for the normally stationary contact, whereby thelatter has provision for limited movement to provide for a quick-makeand a quick-break of the circuit breaker contacts, and for an automaticresetting thereof. upon the tripping of the circuit breaker.

The above and other objects, features and advantages of the presentinvention will be more fully understood from the following descriptionconsidered in connection with the accompanying illustrative drawings.

In the drawings which illustrate the best mode now contemplated by mefor carrying out my invention:

Fig. l is a side view of a circuit breaker, pursuant to the presentinvention, a part of the casing being removed and a portion thereofbeing broken away with the circuit breaker mechanism in the circuit-openor interrupted condition thereof, and parts being illustrated insection;

Fig. 2 is a fragmentary sectional view taken on the line 22 of Fig. 1;

Fig. 3 is a fragmentary side view of the circuit breaker mechanismillustrating the condition thereof in the closed or circuit makingcondition of the circuit breaker;

Fig. 4. is a perspective view, on an enlarged scale, and illustrates thequick-make, quick-break mechanism of the present invention in thecircuit interrupted condition of the circuit breaker; and

Fig. 5 is a diagrammatic illustration of the operation of thequick-make, quick-break mechanism.

In order to facilitate the explanation thereof, the present invention isillustrated and described in connection with a circuit breaker of thetype which is illustrated and described in the copending application ofTracy B. Taylor and Gustave A. Duve, Serial No. 360,522 filed June 9,1953, and assigned to the assignee hereof. However, it will beunderstood that the present invention is,

not limited to the specifically described breaker but may be utilized inother types of breakers.

Referring now to the drawings in detail, there is shown a circuitbreaker 20 which is provided with 2. preferably metallic outerprotective casing 22 in which there is disposed the insulated housing 24which contains the circuit breaker operating mechanism, generallyindicated by the reference numeral 26. The casing 22 hermetically sealsthe circuit breaker operating mechanism 26 2,829,219 l atented Apr. 1,1958.

ice

therein, said casing being a rigid metallic member having a projectingneck 28, the side walls 30 and 32, respectivley, the end walls 34 (ofwhich only one is illustrated) a top wall 36 and a bottom closure plate38. Said plate. is apertured as at 40-40' for receiving the. dependingbottom wall portions 4242 respectively of the housing 24. Terminalmembers 44 and 46 of the circuit breaker extend through the bottom wallportions 42 of the housing and through the apertures of the metalliccasing, the. projecting portion of said terminals being provided withsuitable wiring securing elements, not illustrated herein. It will beunderstood that a suitable sealing compound, is used at the portions ofthe casing and housing through which the terminals extend forhermetically sealing the.

casing at, these points.

Manually operable mechanism 48 for operating the,

circuitbreaker operating mechanism 26 to open and close the latter isprovided in the previously mentioned throat.

portion 28 of the outer casing 22. Said manually oper able mechanism.may be of the type illustrated and described in the copendingapplication of Tracy B. Taylor, Serial No.. 270,297,

be understood that the lever 52, when actuated by hnadle 53, isoperative to move the pin or shaft 58 to and from the positions thereofillustrated in Figs. 1 and 3 for correspondingly. moving the.operating'mechanism 26 of the circuit breaker, as hereinafter describedin detail.

In order to hermetically seal the circuit breaker mechanism 26 withinthe casing, and as illustrated and described in both, of the previouslyidentified copending applications, there is: provided, sealing meanscomprising a flexible resilient tubular member 64 of bellows-likeconstruction having one. peripheral end portion thereof secured to the,neck portion 28. The opposite peripheral end portion 66 of, said tubularmember is provided with a circular plate (not illustrated) which iscentrally apertured and the lever 52 extends through the. aperture insaid plate and is secured thereto in sealing relation in anyconventional manner. It will be understood that the first mentionedperipheral end of the member 64 is suitably sealed within the neckportion 28 so as to hermetically seal the circuit breaker mechanism 26within the casing 22. As the flexible tubular member 64 does not per seconstitute part of the present invention, further decription thereof isdeemed to be unnecessary herein, the same being fully described indetail in said copending applications.

As previously indicated, the circuit breaker operating mechanism 26 iscontained within the previously men tioned housing 24, formed of thecompanion housing parts 63 and 76 which are preferably molded from asuitable insulation material, and which are mutually secured in housingdefining relation, as by the securing elements 72. The housing isprovided with an opening 74 in the upper end thereof between saidhousing parts so that the lever 52 may be operatively connected with thepin member 58, as previously described. As previously indicated, the pinmember 558 extends between a pair of spaced substantially triangularshaped and insulated pivoted levers or yoke members 60. Said yokemembers are mounted upon the shaft member 76 which is provided with the.end pivot porfiled February 7, 1952, issued as- Patent No. 2,718,575 onSeptember 20, 1955, and asg the function of which will presently appear.

3 tions 78 which have bearing support in the confronting bearingportions 80 provided in the housing parts 68 and 70, respectively. Itwill be noted that the shaft 76 is provided with a sleeve 81 whichserves to space the yoke members 60. From the foregoing, it will beapparent that the previously described actuation of the lever 52 willresult in the pivotal movement of the yoke members to and from thepositions thereof illustrated in Figs. 1 and 3, due to the operativeconnection between the lever 52 and the pin 58 carried by said yokemembers. It will be noted that the pin 58 interconnects thesubstantially triangular yoke members at one of the corners thereof, asecond corner of said yoke members being interconnected by the pivotmember 82 and the third corner being provided, pursuant to the presentinvention with a recess 84,

Said member 82 pivotally mounts the spaced links 86-86. At the other endthereof, the links carry the pin member 88 which pivotally mounts theactuating lever 90 of the circuit breaker mechanism 26.

The actuating lever or actuator 90 is bodily carried by a movable switchassembly 92 of the circuit breaker operating mechanism. Said movableswitch assembly comprises the movable switch member 94 which ispreferably formed of insulating material, a conducting arm 96 and acompanion arm 98 which is formed of insulating material. The movableswitch member 94 is provided, in termediate the ends thereof, with theupwardly extending pivot portion 100 which is provided with a pivotmember 102 which is suitably mounted in the companion housing members 68and 70. It will be understood that the companion arms 96 and 98 straddlethe pivot portion 100 and that the pivot member 102 extends through saidarms. A pivot pin 104 pivotally mounts the actuating lever 90 betweensaid arms 96 and 98.

In order to releasably latch the actuating lever 90 to the movableswitch member assembly, the movable switch member 94 is provided with alatch element or catch 106. The member 94 is provided with an adjustingelement 108 to effect the axial movement of the latch 106 for adjustingthe extent of overlap of the latch with the free end 110 of theactuating lever 90 for calibrating the circuit breaker mechanism.

The current control device for the circuit breaker mechanism isconstituted by a bimetallic element 112 which is interposed between thecompanion arms 96 and 98, on the one hand, and the movable switch member94, on the other hand, between the pivot 102 and the latch element 106.In this connection, it will be understood that the bimetal 112 isprovided with a looped portion 114 which forms parallel arms one ofwhich bears against the movable switch member 94 and the other of whichbears against the companion arms 96 and 98, as fully illustrated anddescribed in the previously identified application of Taylor and Duve.Said bimetallic element 112 is connected in circuit through the circuitbreaker, one end of the bimetal being electrically connected, as by thepin 116, to the conducting arm 96 and the other end being connected by asuitable flexible conductor (not illustrated) to the terminal 44. In theengaged condition of the circuit breaker, as in Fig. 3, the circuit iscompleted by the engagement of the companion contacts 118 and 120,movable contact 118 being carried by the conducting arm or movablecontact support 96 and contact 120 being connected by means of theflexible conductor 122 to the terminal member 46. It will be understoodthat when the bimetal 112 is subjected to suflicient heat to cause it toflex, the arms provided in the looped portion 114 thereof move inopposite directions to effect relative movement of the movable switchmember 94 and the companion arms 96 and 98, the latter moving as a unit,in a direction to disengage the actuating lever 90 from the latch 106.

From the foregoing, it will be apparent that the movement of the handleoperated lever 52 from the o to the on position thereof will result inthe pivotal movement thereof from the position thereof illustrated inFig. 1, to the full-line position thereof illustrated in Fig. 3, formovement of the shaft 58 as illustrated in said figures. Said movementof the shaft results in the clockwise rotation of the companion yokes tothe position thereof illustrated in Fig. 3. During said movement of theyokes, the springs 101, which interconnect the yokes and the switchassembly 92, are tensioned, the companion links 86 move the free end 110of the actuating lever into engagement with the companion latch 106, andcontinued movement of the operating handle in the same direction, aftersaid engagement of the latch 106, results in the pivotal movement of themovable switch member assembly. 92 to the closed condition thereof, asillustrated in Fig. 3' wherein the companion contacts are in engagement.This completes the circuit between the terminals 44 and 46 and, upon anoverload or other abnormal current condition, it will be understood thatthe bimetallic control element 112 will flex so that the arms thereofwill move in opposite directions whereby to cause relative pivotalmovement of the movable switch member 94 and the companion arms 96 and98. This results in the disengagement of the latch 106 from theactuating lever 90 and the movement of the movable switch assembly tothe open position thereof, by the contraction of the springs 101,interconnected between the yokes and the movable switch assembly 92, toopen the breaken In this connection, it will be understood that in theclosed condition of the cir cuit breaker mechanism, there is a normallyoverset toggle constituted by the yokes 60, which form one arm of thetoggle, and the links 86 which form the other arm of the toggle. It willbe noted that in the closed condition of the breaker, the intermediatetoggle axis, at 82, is to the left of or above a line extending betweenthe outer toggle axes, as will be apparent from Fig. 3 and as shown infull line in Fig. 5 wherein 88A and 82A represents the movable toggleaxes in their closed position. Furthermore, it will be noted that thecompanion springs 101 are stressed in said closed condition of thecircuit breaker. Therefore, upon disengagement of the latch from theactuating lever, the springs 101 are effective to cause the collapse ofthe toggle and the pivotal movement of the movable switch assembly tothe open position thereof, as in Fig. l. The springs are also effectiveupon automatic tripping of the breaker, to rotate the companion yokes tothe position thereof illustrated in Fig. 1, resulting in the movement ofthe shaft member 58 in a direction to move the lever 52 and therebyautomatically move the handle 53 from the on position thereof, as shownin full line in Fig. 3, to the off position thereof, as shown in brokenline, and 'as illustrated in said previously identified application ofTaylor and Duve. Therefore, it will be apparent that the springs 101,operating upon the yokes 60, serve to automatically reset the handleupon the tripping of the breaker. The circuit breaker can be manuallyoperated to the off position by movement of the handle to the oifposition whereby to rotate the yokes 60 to the position thereofillustrated in Fig. l, to collapse the toggle and permit the springs 101to rotate the movable switch assembly to off position thereof.

In order to provide for ambient temperature compensation provision ismade for a second bimetallic element 121 which is similar inconstruction and in operation to the previously described bimetallicelement 112, the latter constituting the current control device for thecircuit breaker. The bimetallic element 121 is also provided with alooped portion 123 which has spaced parallel arms inbeing understoodthat it is not electrically connectedtq the conductive arm 96, asillustrated and described'in, said copending application of Taylor andDuve.

It will be noted that the control bimetal 112 and, the, compensatingbimetal 121 are disposed at the opposite sides of the pivot 102,substantially at the same distance therefrom. The ambient temperaturewill effect both of said metals in the same manner. Therefore, it willbe readily apparent that when the ambient temperature tends to deflectthe current control bimetal for the companion arms 96 and 98 so that thelatter pivot as a unit relative to the switch member 94', in a.direction to effect the separation of the latch 106 from the actuator91], the compensating bimetalwill be affected in the same manner and'tothe same extent by the ambient temperature so as totend todetlect at theother side of the common pivot for effecting relative pivotal movementof said arms'on said movable switch member in the opposite direction.Consequently, the forces orv stresses existing. between the switchmember 94 and both switch arms, as a unit, on the opposite sides of thecommon pivot, which are due to ambient temperature, will tend to cancelout in view of the fact that they are in opposite directions andsubstantially of the same magnitude, whereby to prevent thedisengagement of the latch andthe actuating lever so as to retain thebreaker in the closed condition thereof.

Pursuant to the present invention, provision is made to provide thecircuit breaker with both a quick-make and a quick-break action so thatit will have a high contact-closing speed, which is independent of theoperator, as well as a high contact-opening-speed which is independ entof the operator. In accordance with the present invention, and as bestillustrated in Fig. 4, the normally stationary contact 120 is carried bythe contact member.

150 which is connected by the previously identified flexible lead 122tothe terminal 46. The contact member 150 is providedwith the spacedlegs 152-152. Each of the legs is provided with a pivot member 154 whichis mounted in a bearing portion 156 provided on the adjacent casingmember. The member 150 is also provided with a tie pin 158 which extendsbetween the legs 152, adjacent the contact 12119. In addition to saidmember 150, provision is made for a lever member 16b at each side of thecontact member 150. Each lever member 160 is provided with a pivot 162which is mounted in a rotary bearing 164 formed in the adjacent casingwall. It will be noted that each lever 160 is provided with an arcuatevslot 166 through which the pivot 154 of the adjacent leg 152 of themember 151) extends. In addition, each lever member 166 is provided witha tongue 168 and with an arm 176. It will be understood that the tongues168 are complementary to the previously mentioned recesses 84 defined inthe yokes 60 so as to be engageable therein, respectively. Tongue 168may be crudely compared to a gear tooth of a driven gear movable onshaft 162, and recesses 84 in yokes 60 may be similarly compared to gear-tooth-rece'iving spaces of drive gears movable on shaft 78, withtongue 168 resembling a gear-tooth fitting loosely in the space 84. Theloose fit of spaces 84 about tongues 1651 enables yokes 61 to movethrough relatively wide angles in actuating the linkage including member86', etc., without driving tongues 168 except at the appropriate times,as more fully explained hereinafter. The motion of yokes s is idle inrespect to drive of tongues 168 for much of the operating strokes ofmanual operating element or lever 52; and this loose fit of tongues 168in spaces 84 thus forms part of what may be termed a floating or alost-motion connection. Consequently it will be apparent that there is afloating linkage or connection between the links ldtl and the yokes 61?.The arms 170 are off-set inwardly of the associated tongues so as toextend between the yokes. Said arms mount a tie pin 172 which cooperateswith the previously mentioned tie pin 158 to secure a tension spring 174between the member 150 and the levers 160, as best illustrated in Fig.4.

From the foregoing, itwill be understood that the con: tact memberandthe levers constitute cooperating toggle elements, the spring 174being an overcentering spring for the toggle to provide a snap actiontherefor. The pivots 154 constitute the intermediate or central fixedaxis of the toggle and the tie pins 158. and 172 constitute the outermovable axes of said toggle. It will bev noted that the spring 174 is a,tension spring, and in the open condition of the circuit breaker, asillustrated in Fig. 1, said spring is under tension and serves to, holdthe contact member 150 in the open or disengaged position thereof.

Referring now to Figure 5, there is a, diagrammatic. illustration of theoperation of the toggle constituted by the contact member 150 and thetogglelevers 160, which is hereinafter referred to, as the stationarycontact. toggle, and is designated as T1 in Fig. 5, the previously mentioned toggle constituted by the yokes 60 and the links 86, foroperating the movable switch, or contact assembly 92, being generallydesignated, at T2 in said Figure 5. In the open condition ofthecircuitbreaker, the axes or centers of toggle T1 are indicated infull line at 172, 154 and 158 which represent the axis of the spring tiepin 172, the axis of the pivot members 154, and the axis of the otherspring tie pin 158, respectively, the axes 172 and 158 being above theaxis 154, as indicated by the solid line 173. In the closed or circuitmaking condition,

of the breaker, the toggle axis 172 is indicated in broken line at 172A,and the toggle axis 158 is indicated in broken line at 1153A, said axesbeing belowv the fixed axis 154, as indicated by the broken line 173A.When the lever 52 is operated from theposition thereof illus-- trated inFig. l to the full line position thereof illustrated in Fig. 3, in orderto close the circuit breaker, the; resultant clockwise movement of theyokes 60 results,

in the pivotal movement of the toggle levers 160, about their pivotalaxes 162, due to the floating connection of the tongues 168 and therecesses 84. This resultsin movement of the toggle axis 172 in thedirection ofthe arrow 180 in Fig. 5. C1 indicates the dead centerposition through which the pivotal axis 172 moves during the closingoperation of the circuit breaker mechanism. It will be apparent that asthe toggle axis 172 passes through its dead center position C1, thespring 174 overcenters to elfect the movement of the toggle outer axes172 and 158 to their positions indicated at 172A and 158A, respectively.This is accomplished with a snap action due to the overcentering of thespring and results in the snap action movement of the normallystationary contact 12.9, from the position thereof illustrated in Fig. 1to the position thereof illustrated in Fig. 3, so as to provide a highcontact closing speed for the contact 120 which speed is independent ofthe operator. Referring now to the concomittant action of toggle T2, thestationary toggle axis is indicated at 78 in Fig. 5, the intermediatetoggle axis in the open position of the circuit breaker being indicatedin broken line at 82 and the other outer toggle axis, in the openposition of the circuitbreaker, being indicated in broken line at 88. Itwill be apparent that: as the yokes 60 are moved from the circuit opento the circuit closed disposition thereof to overcenter the toggle T2,as described, the toggle axis 82 of toggle T2 is moving in an arcuatepath toward, the position thereof illustrated at 82A, and the toggleaxis at 83 is moving in an a'rcuate direction toward the positionthereof illustrated at 88A, and when the toggle axis 82 passes beyondits dead center position, the toggle is overcentered and the switchassembly 92 is moved to the circuit closed condition thereof wherein themovable contact 118 is disposed, as illustrated in Figure 3, forengagement by the normally stationary contact 120. In this closed andengaged condition of the contacts, the spring 174 of the toggle T1 isunder tension and provides a resultant component of force, as indicatedby the.

arrow 175 in Fig. 3, which tends to press the, contact 120 I 'the togglein the opposite direction.

I against the contact 118 to "provide fordesired contact pressure in theclosed condition of the circuit breaker. As a result of the openingmovement of the circuit breaker mechanism, whether accomplished manuallyby operation of the handle 53, or automatically in response to overloador other abnormal circuit condition, the

counter clockwise movement of the yokes 60, from the toggle axis 172 inthe course of its movement from its closed to its open position, and itwill be understood --that when the toggle axis 172 passes through itsdead center position C2 from its position at 172A, the spring 174overcenters and effects a snap action movement of Consequently, thetoggle axis 158 is moved from its closedposition illustrated at 1158A,to its open position illustrated at 158,

to effect a quiclobreak movement of the normally stationary contact 120,from its position illustrated in Fig. 3, to its position illustrated inFig. 1, the speed of which movement is relatively high and independentof the op erator. It will be understood that during said openingoperation of the toggle T1, the toggle T2 is also being operated to itsopen condition during which the toggle center 82 moves from its fullline position illustrated at 82A to its broken line position illustratedat 82.

It will be noted that upon tripping, the circuit breaker isautomatically reset at the end of the opening movement of the circuitbreaker mechanism 92, the handle 53 being disposed in its full 011position, and the contact 129 also being disposed in its full offposition. The automatic resetting of the handle is accomplished by themovement of the yokes 60, under the control of springs 101, to the fulloff position thereof, due to the fact that the toggle levers 160 and thetoggle spring 174 exert negligible force or pressure on the yokes 60.

' Therefore, they do not interfere with the action of the springs 101 inopening the circuit breaker and moving the yokes 60 to the full offposition thereof, as in Fig. l, for disposing the handle 53 in its fulloff position. This results from the fact that there is no directconnection between the yokes 60 and the toggle levers 160, saidconnection being a floating connection, as previously described. In thisconnection, it will also be noted that the length of the toggle spring174 changes very little from its off position, as in Fig. l, to its onposition as in Fig. 3, due to the disposition of the axes of toggle T1.More specifically, the spring tie pin or axis 158 is aligned with andpositioned quite close to the toggle pivots which constitute the axis154, it being noted that the tie pins or axis 158 is positioned muchcloser to said axis 154 than is the companion spring tie pin or axis172. Further, it will be noted that the arcuate path described by thetie pin or axis 172 in moving from its off to its on position causesonly a very slight extension of the spring 174. Consequently, only veryslight additional force is required of the, springs 101 when resettingthe handle 53 on tripping of the breaker, to operate the toggle T1 toits open condition to provide a quick-break of the contacts.

In view of the foregoing, it will be apparent that the actions of thetoggles T1 and T2 are inter-related. More specifically, the toggle T1begins to move from its position indicated by the centers 172A, 154 and158A, in Fig. 5, and passes through its dead center position indicatedby C2, 154 and 158A, before the movable contact 118 is moved from itsclosed position illustrated in Fig. 3. In this connection, it will beunderstood that, as the yokes 60 are moving in a counter clockwisedirection from the thereof illustrated at 172 in Fig. 5., The brokenline position C2 indicates the dead center position for the positionthereof illustrated in Fig. 3, the contact pressure exerted by thecontact 118 against the contact 120 increases as the toggle T2 is movingtoward the straight line position 182 thereof, and more specifically, asthe toggle center at 82A is moving toward said dead center line 182.Then, as the central toggle axis passes through the dead center line132, the pressure exerted by the movable contact member 118 decreasesand returns to the original pressure exerted by the toggle T2, and theaction is such that the toggle T1 moves and passes beyond its deadcenter position C2, 154 and 158A, before the toggle T2 passessubstantially through and beyond its dead center position as indicatedby the line 182 during the opening movement thereof. More specifically,toggle T1 overcenters in contact separating direction substantially whentoggle T2 is moving between the dead center line 182 and the axisposition 828, in. Fig. 5, and before .toggle T2 reaches its openposition.

From the foregoing, it will be apparent that the present inventionprovides for both a quick-make and a quick break circuit breaker whichis automatically reset, and in the combination of the quick break andthe automatic reset operation the force which is required to move theelements of the toggle T1 to the o position thereof, is very small.Since provision is made for a toggle spring which is originally undertension, only a slight additional force beyond the original tension ofthe spring is required to operate the toggle T1 to its open condition.

, This is due to the fact that the toggle centers or toggle axes of thetoggle T1 are so disposed that the length of the toggle spring 174changes only very slightly since it moves along an are which iscomparatively quite slight.

It will be noted that a detent for the contact member 150, in the opencondition thereof, is provided by an overlying casing portion 186. Thestationary pivots 154, which extend through the arcuate slot 166provided in the toggle levers 160, constitute a detent for said togglelevers in both the open and closed conditions thereof, as bestillustrated in Figs. 4 and 3, respectively.

Provision is also made in the present construction, to compensate orneutralize mechanical shocks and vibrations. In this connection,provision is made for an inertia latch assembly as provided for in saidpreviously identified application of Taylor and Duve. Said assembly isconstituted by the inertia latch piece and the inertia latch spring 132.The latch piece 130 is suitably connected to the pivot or shaft member58 and is mounted in suitable guideways provided in the housing 24 forreciprocation in the direction of the arrows 134, the guideways beingindicated at 137. The latch piece is also provided with a substantiallysquare aperture 136. The inertia spring 132 is looped or bent betweenthe ends thereof and is mounted on a securing element 72. It will beunderstood that the housing has suitable provision to retain the latchspring 132 in the operative disposition thereof illustrated in Fig. 1,the spring being provided at the free ends thereof with weights orcatches 138 which are dimensioned to enter the aperture 136. In theclosed condition of the breaker, it will be understood that the catches138, are in registry with the aperture 136 and straddle the latter, asillustrated in the copending application of Taylor and Duve. In the opencondition of the circuit breaker, the catches are disposed asillustrated as in Fig. 1.

If, with the mechanism 26 in the closed condition thereof, the circuitbreaker 26 is subjected to a blow or a shock in the direction of thearrow 140, the upper catch 138 will engage in the aperture 136 toprevent the counter clockwise rotation of the yokes about their axis 78,due to the shock forces acting upon the manually operable actuatingmechanism, and thereby prevent the collapse of the toggle and theconsequent opening of the circuit breaker. In the same manner, in theevent of a shock or a blow in the direction of the arrow 142, in theclosed condition of the circuit breaker, the lower catch 138 will beengaged in the aperture 136 of the latch piece to pro With the circuitbreaker mechanism inzthe open condition thereof, as illustrated in Fig.l, the latchpiece 130 is disposed outwardly of the opposing arms of thespring 132. Assuming-a shock in the direction ofthearrow 140, thetendency of the yokes will be to rotate in the clockwise direction sothat the latch member will tend to move into position between the armsof the spring 132; However, in the event of such an occurrence, theupper spring catch 13% moves into position behind the free end 144 ofthe latch piece 136 to prevent the movement of the latch piece betweenthe spring arms, tov prevent the closing of. the breaker.

Similarly, in the event of a shock or. blow in the direction of thearrow 142, the lower catch 138 is momentarily disposed behind the freeend 144 of the latch piece 130 to preventthe movement of the latch pieceto its closed circuit condition and thereby to prevent the closing ofthe circuit breaker mechanism.

To facilitate the previously described operation of the toggle T1, itwill be noted that the shaft 76, whichv mounts the yokes 69, is providedwith a planar portion 77 to provide clearance for the described arcuatemovement. of the free end of the arms 170.

While I have shown and described the preferred embodiments of myinvention, it will be understood that various changes may be made in thepresent invention Withoutdeparting from the underlying ideav orprinciples of the invention within the scope of the appended claims;

Having thus described my invention, What I claim and desire tosecure byLetters Patent is: I

L In an automatic circuit. breaker having: companion relatively movablecontacts, mechanism. to effect engagement and disengagement thereof toclose and. to open the breaker, respectively, and means to automaticallyreset thebreaker upon the tripping thereof, the combination with saidreset means of means to provide a quickemake closing and a quick-breakopening of said contacts, and manually operable means for operating saidmechanism to closeand to open the breaker, said reset means includingspring means operable to move said! manual means to a reset positionthereof upon automatic tripping of the breaker, andsaid quickemakequick-break. means operating under the control of said spring means toeffect a quick-break opening of said. contacts, said quick-makequiclobreak. means including a pair of toggle linkshaving respectivefixed pivots andastressed over-centeringspring which. is subjected toonlyslight change of. length upon either manual operation or automatic.tripping of the breakenwhereby to minimize the amountof force. requiredof said first mentioned spring means to effect both. said resetting ofsaid manual means and said operation ofsaid.

quick-make quick-break means upon automatic tripping of. said breaker.

2. In an automatic circuit breaker having companion relatively movablecontacts disposed for mutual engagement and disengagement to close andopen the breaker, respectively, circuit breaker operating mechanismincluding control means operable to effect automatic. tripping of thebreaker upon the occurrence of predetermined current condition, andspring means operable to open the breaker uponsaid trippingthereof;.that improvement which. comprises theprovision of meansoperable to provide a quick-make closing and a quick-break opening ofsaid contacts, said latter means being operable-under the control ofsaid spring means to effect said quick-break opening of said contacts,said latter means comprising cooperating toggle elements mounted onfixed axes. and carrying. respective movable axes interconnected by astressed over-centering spring, the movable axis of each element beingcloser to the fixed axes of the other. element than the movable axis ofeach element. is to its own fixed axis one of said elements beingprovided with one of said contacts, and theaxes of said. toggle elements10 being so-relatedasto require of'said over-centering spring to efiecta quick-break opening of said contacts, whereby to minimize the force required of said first mentioned spring means in the operation of saidlatter means to effect a quick-break opening of said contacts.

3. In an automatic circuit breaker having companion relatively movablecontacts disposed for mutual engage ment and disengagement to close andopen the breaker,.

respectively, circuit breaker operating mechanism including controlmeans operable to elfect automatic tripping of the breaker upon theoccurrence of predetermined current condition, and spring means operableto open the breaker upon said tripping thereof; that improvementv whichcomprises the provision of means operable to provide a quick-makeclosing and a quick-break opening of' said contacts, said latter meansbeing operable under the control of said spring means to effect saidquick-break opening of said contacts, said latter means comprising,cooperating toggle elements mounted on fixed axes and' carryingrespective movable axes, a first one of said elements bearing one ofsaid contacts and the other of said elements having a lost motionconnection to said. circuit breaker operating mechanism interconnectedby a stressed over-centering spring, the movable axis of each elementbeing closer to the fixed axis of the other element than the movableaxis ofeach element is to its own fixed axis and said other elementbeing arranged to shift the line of action of said over-centering springfrom one side of the fixed axis of said contact-bearing element to theother side thereof and reversely in coordination with operation of saidcircuit breaker operating mechanism, one of said elements being providedwith one of'said' contacts, and the axes. of said toggle elements beingso related as to require only slight change of length of saidover-centering spring to efiect a quick-break opening of said contacts,whereby to minimize the force required of said first men? tioned springmeans in the operation of said latter meansv to effect a quick-breakopening of said contacts, and manually operable means for operating saidcircuit breaker mechanism and thereby operating said toggle elements forboth opening and closing the circuit breaker in quickmake andquick-break fashion and said spring means being elfective in response toautomatic tripping to operate said linkage and said manually operablemeans when.

tacts, respectively, actuating means for operatively etTecting theengagement thereof, current-responsive control means for effecting thedisengagement thereof, a handle for manually operating said actuatingmeans and movable to and from circuit-open and circuit-closed positions,and spring means for opening the breaker and operable to move saidhandle to said circuit-open position thereof upon tripping of thebreaker; means to provide a quick-make closing and a quick-break openingof said breaker, and. link means operable between said handle and saidspring means, said link means having an operative engagement with saidquick-make quick-break means, whereby said quick-make closing isinitiated by said handle and said said quick-break opening is initiatedby said spring means under control of said current-responsive means,said quickmake quick-break means comprising cooperating toggle elementshaving fixed pivots and being interconnected by a stressedover-centering spring, one of said elements being provided with one ofsaid contacts, and the axes of said toggle elements being so related asto require only slight change of length of saidv over-centering springto effect a quick-break opening of said contacts, whereby to minimizethe force required of said first mentioned spring. means in theoperation of said latter means to eifect a quick-break opening of saidcontacts.

5. Inv an automatic circuit breaker having relatively only slight changeofllength.

ii1ovalil'e contact members provided with companion contacts,respectively, actuating means for operatively effectmove said handle tosaid circuit-open position thereof upon tripping of the breaker; meansto provide a quick-make closing and a quick-break opening of saidbreaker, and pivotally mounted yoke means operatively engaged with eachof said actuating means, said handle and said spring means, said yokemeans having a floating connection with said quick-make quick-breakmeans, whereby said quickmake closing is initiated by said handle andsaid quickbreak opening is initiated by said spring means.

6. In an automatic circuit breaker having relatively movable contactmembers provided with companion contacts, respectively, actuating meansfor operatively effecting the engagement thereof, current-responsivecontrol means for effecting the disengagement thereof, a handle formanually operating said actuating means and movable to and fromcircuit-open and circuit-closed positions, and

spring means for opening the breaker and operable to move said handle tosaid circuit-open position thereof upon tripping of the breaker; meansto provide a quickmake closing and a quick-break opening of saidbreaker,

and pivotally mounted yoke means operatively engaged with each of saidactuating means, said handle and said spring means, said yoke meanshaving a floating connec- 'tion with said quick-make quick-break means,whereby said quick-make closing is initiated by said handle and saidquick-break opening is initiated by said spring means, said quick-makequick-break means being provided with one of said contacts and includinga stressed over-centering spring connected to require only negligibleadditional stressing to eliect a quick-break opening of said contacts,whereby to minimize the force required of said first mentioned springmeans in the operation of said latter means to effect a quick-breakopening of said contacts.

7. In an automatic circuit breaker, companion relatively movablecontacts, operating mechanism for said contacts including a movablecontact support, an actuating member, spring means biasing said supportin the direction to open the contacts and biasing said actuating memberin the resetting direction, mechanism restraining said support and saidmember against said spring bias with the contacts closed and with theactuating member in closedcontact disposition, the foregoing beingarranged to open said contacts and reset said actuating member uponrelease of the restraining means, and quick-make, quickbreak operatingmeans for one of said contacts operated conjointly with said actuatingmember.

8. In an automatic circuit breaker, companion relatively movablecontacts, operating mechanism for said contacts including a movablecontact support, an actuating member, spring means biasing said supportin the direction to open the contacts and biasing said actuating membertoward the reset position, mechanism restraining said support and saidmember against said spring bias and including a latch movable in onedirection upon release of the restrained movable support and movable inthe opposite direction after release and during movement of saidactuating member toward reset position, and means coordinated with saidactuating member for effecting quick-closing and quick-opening of saidcontacts.

9. An automatic circuit breaker having first and second separablemovable contacts, a manual operating element, a linkage between saidmanual element and one of said contacts including a first movablecontact-bearing arm, overload release means and means cooperable withsaid first arm and said overload release means and operable by saidmanual operating element for shifting said first contact from open toclosed position, said linkage having a spring effective to bias saidfirst contact-bearing arm and'said linkage and said manual operatingelement into their respective open positions, said second contact havinga second movable contact-bearing arm and an over-center spring devicefor snap-operating the second contact between open and closed positionsand reversely, said over-center spring device having a drive connectionto said linkage for operation thereby.

10. An automatic circuit breaker, including a manual operating elementmovable in a stroke between on and 0E limits, a pair of separablecontacts, mechanism operable to open and close said contacts, saidmechanism including an over-centering spring device actuated by themanual operating element for causing snap-opening and snap-closing ofthe contacts when the manual operating element is operated through itssaid stroke, said mechanism also including overload release means and a'springbiased releaseable mechanism controlled therebyand effective inresponse to overload to cause trip-free snapopening of the contacts andoperation of the manual operating element from its on limit to its ofilimit when not externally restrained, said spring-biased mechanismhaving an operative connection to said over-centering spring device forreturning said device to its oil condition concurrently with theoperation of the manual operating element to its off position.

11. An automatic circuit breaker, including a manual operating elementmovable in a stroke between circuitopen and circuit-closed limits, apair of separable contacts, an over-center spring device having anoperating connection to said manual operating element for operating saidover-center spring device to effect snap-opening and snapclosing of thecontacts in response to manual operation of the circuit-breaker, andfurther mechanism including an overload responsive element and a springarranged to cause snap-opening of the contacts in response to anoverload and said further mechanism including said spring beingthereupon efiective to bias said manual operating element towardcircuit-open position and said further mechanism having a driveconnection to said over-center spring device to operate said over-centerspring device into its circuit-open position, when the manual operatingelement is returned to its circuit-open position.

12. An automatic circuit breaker including a manual operating element, apair of separable contacts, and separate mechanisms operable by saidmanual operating element for operating said contacts betweencircuit-open and circuit-closed positions, one of said mechanismsincluding a trip-free overload release mechanism and a spring ef fectivefor snap-opening the contacts in response to an overload and,independently, for thereupon returning said element to its circuit-openposition, the other of said mechanisms having a snap-acting over-centerspring device movable between circuit-open and circuit-closed positionsby said manual operating element and movable to said circuit-openposition by said spring as an incident of return of the manual operatingelement to circuit-open position in response to an overload.

13. An automatic circuit breaker including a manual operating element, apair of separable contacts, and separate mechanisms operable by saidmanual operating element for operating said contacts betweencircuit-open and circuit-closed positions, one of said mechanismsincluding a first contact-operating arm, a toggle linkage providing adrive connection between said manual operating element and said firstarm, an overload release mechanism, and a spring biasing said firstcontact bearing arm in the circuitopen direction when the contacts areclosed and said spring being effective upon release of the overloadrelease mechanism for snap-opening the contacts and, when said manualoperating element is unrestrained, for returning said element to itscircuit-open position, the other said mechanisms having a snap-actingover-center spring device including a second contact-operating armbetween circuitopen and circuit-closed positions, and having alost-motion connection to said one mechanism for operation by said 13manual operating element and movable to said circuitopen position bysaid spring as an incident of return motion of the manual operatingelements to its circuit-open position in response to an overload.

14. An automatic circuit breaker including a pair of separable contacts,a manual operating element, a snapacting mechanism operable by saidelement for both snapopening and snap-closing said contacts, anautomatic contact operating mechanism additional to said snap-actingmechanism and including overload release means for effecting trip-freerelease of the contacts in response to an overload, said automaticmechanism including a spring operative for snap-opening of the contactsand to return said manual operating element and said snap-actingmechanism to their respective circuit-open positions in response to anoverload.

15. An automatic circuit breaker including a pair of separable contacts,a manual operating element, a first mechanism for operating one of saidcontacts including a contact-bearing arm, an overload release devicemovably carried with said contact-bearing arm, and a trip-free inkagebetween said manual operating element and said contact-bearing arm andincluding a spring for biasing said manual operating element towardcircuit-open position, an overcenter spring device for snap-opening andsnap-closing the second of said separable contacts and including alost-motion connection to said manual operating element.

16. An automatic circuit breaker including a pair of separable contacts,a manual operating element, first and second mechanisms both operable bythe manual operating element for moving said contacts intocircuit-closed position, one of said mechanisms including a togglelinkage progressively operable by said manual operating element formoving one of said contacts to its circuit-closed position and forretaining said manual operating element in its circuit-closed positionand a spring arranged to bias said one contact toward circuit-openposition and said one mechanism further including overload release meanseffective when released to enable said spring to cause snapopening ofthe contacts and return of said manual operating element to itscircuit-open position, the other of said mechanisms including asnap-acting over-centering spring mechanism operable for bothsnap-opening and snapclosing said contacts and said second mechanismincluding a pair of elements each having a fixed pivot and said elementsbeing interconnected by an overcentering spring, said second mechanismbeing mechanically coordinated with said manual operating element formotion of both said second mechanism and said manual operating elementfor motion of both said second mechanism and said manual operatingelement between respective circuit-open and circuit-closed positions.

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